This invention relates to automatic liquid level control systems and more particularly to an automatic liquid level control system for use on an separation tank system.
Separation tanks are often used to separate pollutants from waste water discharges from industrial processes before the water is permitted to be discharged into a natural body of water. Obviously, it is desirable to operate these tanks in an efficient manner so that any possibility of polluting the nearby streams is minimized. One aspect of the separation tank operation which relates to its efficiency for controlling the quality of the effluent water discharged from the tank, is the maintenance of the liquid level within the tank within predetermined tolerances. Normally, this level control operation has been done manually. When influent flow rates remain constant or vary in a predictable manner, this particular method is adequate. However, there are often times when the influent flow rates can vary quite rapidly and unpredictably. These conditions require continuous monitoring of the liquid level within the separation tank so that the efficiency of the air flotation tank is maintained. It is therefore desirable to have an automatic system for controlling the liquid level to reduce the manpower requirement for operating separation tanks as well as to improve control over the process.